For example, in an area that is a mountain area or the like and where it is difficult to install communication equipment using a wired line such as an optical line because of the topography of the area or an environment of the area, a radio communication network system is built using an access point (AP) such as a Wireless Fidelity (Wi-Fi) access point in some cases. In the radio communication network system, the AP collects and accumulates log information of a surveillance camera for security or the like and collects log information of user access for a coupon distribution service or the like.
FIG. 1 is a diagram illustrating an example of the topography of a mountain area where a radio communication network system is built. In the example illustrated in FIG. 1, the mountain area includes areas used as ski areas, predicted danger areas where the occurrence of an avalanche is predicted, a danger area in which general people are prohibited to enter, a restricted area, and the like. In the example illustrated in FIG. 1, the radio communication system is built so as to cover the ski areas.
FIG. 2 is a diagram illustrating an example of a configuration of the radio communication network system that is illustrated in FIG. 1 and is built so as to cover the ski areas. The radio communication network system includes multiple APs P1 installed at predetermined positions in the ski areas, predicted danger areas located around the ski areas, and the like and includes a monitoring operation server P2 that is located away from the ski areas at a position where the monitoring operation server P2 is not affected by an avalanche.
Each of the APs may operate as an access point that outputs a monitoring signal such as a beacon signal and is connected to a user terminal for the purpose of use in some cases. Each of the APs may operate as a bridge that relays radio communication between access points without transmitting a monitoring signal in some cases. In FIG. 2, each of APs that operate as bridges is indicated by “BR” (bridge). Hereinafter, when an access point operates as an access point, the access point is indicated by “AP”. Hereinafter, an access point that serves as a device is indicated as a radio relay device.
The monitoring operation server P2 monitors the radio relay devices P1, executes a process of detecting a failure, receives an avalanche alert message from an avalanche prediction system P3, and notifies the radio relay devices P1 included in the radio communication network system of the avalanche alert message. The avalanche prediction system P3 is a system for predicting the occurrence of an avalanche based on topography, weather, the state of accumulated snow, and the like. The monitoring operation system P2 connects the radio communication network system to the Internet.
Examples of related art are Japanese Laid-open Patent Publications Nos. 2010-28369 and 2003-18073.